Contact surface adapter and components for artificial prosthesis installation clamp

ABSTRACT

In the use of devices and methods for measuring applied pressure on an article, such as a patella construct during a surgical procedure, differently sized and configured clamp bushing adapters can be interchangeably employed with, and removably secured to, a clamp stem to adapt to the relative sizes of objects being clamped. Embodiments of an installation cap can also be provided to assist with proper setup and operation by, for example, removably covering spike elements associated with a working surface of embodiments of the device.

TECHNICAL FIELD

The present invention relates to medical instrumentation, and moreparticularly to a device for adapting the contact surface or surfaces ofan artificial prosthesis installation clamp.

BACKGROUND ART

The typical known art of surgically resurfacing the natural patella,when necessary to accept an artificial patella prosthesis, requires thepatella to be everted and held in a position allowing the surgeon tohave access to the articulating surface which normally articulateswithin the intercondylar notch between the femoral condyles.

The natural patella is first measured, establishing its exact thickness,after which the surgeon resects the appropriate thickness of theposterior portion of the natural patella, and then prepares the surfaceto receive the artificial patella prosthesis. A patella trialreplicating the actual implant to be installed is placed upon theprepared patella surface to confirm proper fit and thickness of thepatella construct that establishes proper ligamentous tension foroptimum stability and range of motion whereupon, a bonding agent (e.g.,bone cement) is prepared. In the typical known handling of the bonecement, there is an exact science of measured polymer (e.g., powder) andmonomer (e.g., liquid) packaged sterile in their individual respectivestates delivered into a sterile field placed into and enclosed in asterile container whereupon measured vacuum force is applied and ameasured time of thorough mixing is conducted. The properties arehandled under strict scrutiny and respectful disciplines. When thevacuum is released, the top of the sterile container can be removed,giving access to the bone cement, whereupon it is examined to confirmthat it is in the proper state to be applied. Precautions are generallytaken to create the bone cement and bring it into a proper stableuseable product, whereby it can be applied in order to successfully bondthe aforementioned surfaces. At this juncture, a patella clamp isapplied to the patella construct (which consists of the surgicallyresurfaced posterior aspect of natural patella prepared to receive anartificial patella replacement paired with the bonding agent bonecement). However, past methods and devices for applying the pressurehave not been controlled and have resulted in the application of anarbitrary and unknown pressure upon the patella construct until the bonecement is fully cured. As such, less than satisfactory results canoccur.

Measured pressure upon the patella construct is a paramountconsideration to the mechanical properties, scientific quantitation andincreased long-term success of the bonding integrity of the bone cement.Heretofore, no patella clamp has existed for general surgical use whichtakes into account all the parameters and dynamics taking place withinthe patella construct as it relates to all surfaces involved and thescientific and mechanical properties of the bonding agent bone cementduring installation, as well as, the potential of excessive unknownpressure upon the host patella creating micro fractures. Further, pastpatella clamps have not addressed the need for contact surface adaptersand components that protect the user during and after preparation andoperation while providing a disposable component facilitating accuraterelative sizing and post-operative cleaning.

DISCLOSURE OF INVENTION

In various aspects, the present invention enables the medicalprofessional (e.g., a surgeon) to accurately apply positive lineardirectional control and known pressure upon the patella constructthroughout the process to the cure state of the bone cement, whileprotecting the professional during and after preparation and operationwhile providing a disposable component facilitating accurate relativesizing and post-operative cleaning. After the initial proper pressure isestablished upon the patella construct, certain variables can come intoplay affecting the applied pressure. In various aspects, the presentinvention allows the attending medical professional(s) to stay informedas to pressure changes, giving the medical professional(s) thecapability to re-establish correct pressure by known positive control.

Aspects and embodiments of the current inventive device receive theeverted patella in its prepared form whereupon the anterior portion ofthe natural patella is placed upon a spiked platform of a bottom plateassociated with the various embodiments of the device. The adapter andcomponents according to embodiments of the present invention cover thespiked platform before and after use while further providing adisposable component facilitating accurate relative sizing andpost-operative cleaning. Upon the patella being held in place, thesurgeon or other medical professional takes hold of the knob of the knobassembly of the present device, holding it firmly in one hand. With theother hand, the medical professional depresses a quick release button ofone embodiment of the present device, freeing the adjustment rodthereupon. As the medical professional pushes downward atop the knob inthis embodiment, the indicating assembly of the present devicetranslates downward in a controlled linear direction as its slide ringhouses and translates upon the keyed guide rod acting as an establishedvertical stable construct. When the patella bushing or adapter device ofthe present invention makes contact with the artificial patella of thepatella construct, the medical professional can apply controlledpressure, and an indicating assembly measures the pressure being appliedand an assembly contained calibrated indicator gives visual knowledgeand reference as to the precise amount of measured applied pressurebeing applied.

In alternative embodiments, a medical professional secures anappropriately sized and configured insert into the device, ensures thatthe everted patella is appropriately situated in the receiving area ofthe device, and adjusts a knob assembly to a desired level associatedwith a measured pressure.

Upon the surgeon creating the specific required and known appliedpressure, the clockwise turning motion upon the assembly knob can beterminated. At this time, the bonding agent within the patella constructwill squeegee out; the bottom platform spikes will depress into theanterior patella and the bushing (e.g., a rubber bushing or of othermaterial and design) in the stem of the clamp indicating assembly cansettle in. It will be appreciated that the above processes can takeeffect within seconds and the amount of applied pressure can thereafterdecrease.

Thereupon, the present inventive device indicator visually informs themedical professional(s) of the potential adverse change in pressure andthis calibrated reference gives the necessary information to correct andre-establish proper pressure. In the event of change from optimumapplied pressure, the medical professional can create additional neededknown applied pressure by again turning the assembly knob tore-establish the precise prescribed pressure to be upon the patellaconstruct. The present invention thus, in part, enables the medicalprofessional to create and maintain measured applied pressure upon thepatella construct until the bone cement is fully cured. Upon theprofessional confirming the bone cement is fully cured, the presentdevice can be removed by turning the knob in the opposite direction fromthe direction used to apply pressure, thereby relieving pressure off theindicating device. An adapter device secured to the clamp can then bediscarded and the clamp device thoroughly cleaned, particularly aroundareas close to the operative procedure so as to be appropriatelyprepared for further use.

Among other things, the present invention substantially improvesprocedures in the installation of an artificial patella prostheticreplacement in total knee arthroplasty and is also introductory toadditional improvements within a system of surgical instrumentation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an assembled version of one embodimentof a clamp device employable with embodiments of the present invention.

FIG. 2 is a perspective view of an assembled version of an alternativeembodiment of a clamp device employable with embodiments of the presentinvention.

FIG. 3 is a perspective view of an embodiment of a knob assembly portionemployable with embodiments of the present invention.

FIG. 4 is a perspective view of an embodiment of a guide rod sleeveemployable with embodiments of the present invention.

FIG. 5 is a perspective view of an embodiment of a slide platformportion of a clamp indicating assembly employable with embodiments ofthe present invention.

FIG. 6 is a top plan view of elements of an embodiment of a pressuremonitor assembly employable with embodiments of the present invention.

FIG. 7 is a perspective view of an embodiment of a stem assembly portionof a pressure monitor assembly employable with embodiments of thepresent invention.

FIG. 8 is a perspective view of an embodiment of a guide rod employablewith embodiments of the present invention.

FIG. 9 is a perspective view of an embodiment of a top plate employablewith embodiments of the present invention.

FIG. 10 is a perspective view of an embodiment of a bottom base plateemployable with embodiments of the present invention.

FIG. 11 is a perspective view of an embodiment of a portion of anactuator assembly employable with embodiments of the present invention.

FIG. 12 is a front elevational view of an embodiment of an assembledversion of a clamp device employable with embodiments of the presentinvention.

FIG. 13 is a perspective view of the embodiment of FIG. 12.

FIG. 14 is a front elevational view of one embodiment of a pressuremonitor assembly employable with embodiments of the present invention.

FIG. 15 is a perspective view of one embodiment of a pivot nut elementemployable with embodiments of the present invention.

FIG. 16 is a front elevational view of the pivot nut element of FIG. 15.

FIG. 17 is a perspective view of one embodiment of a bottom base plateemployable with embodiments of the present invention.

FIG. 18 is a perspective view of one embodiment of a clamp stem elementemployable with embodiments of the present invention.

FIG. 19 is a cross-sectional view of the clamp stem element taken alongthe line 19-19 of FIG. 18.

FIG. 20 is a perspective view of a clamp stem insert element accordingto embodiments of the present invention.

FIG. 21 is a cross-sectional view of the clamp stem insert element takenalong the line 21-21 of FIG. 20.

FIG. 22 is a front elevational view of an assembled version of anotherembodiment of the present invention.

FIG. 23 is a perspective view of the embodiment of FIG. 22.

FIG. 24 is a cross-sectional view of a pressure monitor assemblyaccording to embodiments of the present invention, as taken along theline A-A of FIG. 22.

FIG. 25 is a perspective view of an alternative embodiment of a clampstem element employable with embodiments of the present invention.

FIG. 26 is a cross-sectional view of the clamp stem element taken alongthe line 26-26 of FIG. 25.

FIG. 27 is a perspective view of a clamp stem insert element inaccordance with embodiments of the present invention.

FIG. 28 is a cross-sectional view of the clamp stem insert element takenalong the line 28-28 of FIG. 27.

FIG. 29 is a perspective view of a clamp base insert element accordingto an embodiment of the present invention.

FIG. 30 is a front view of the clamp base insert element of FIG. 29.

FIG. 31 is a right side view of the clamp base insert element of FIG.29.

MODES FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2 are perspective views of different embodiments of theadjustable measured applied pressure clamp device 20 for use withembodiments of the present invention. As shown in the embodiment in FIG.1, the device 20 comprises a frame assembly 30 for receiving andmaintaining a knob assembly 40 and a clamp indicating assembly 50.

The frame assembly 30 can comprise a bottom base plate 31 and a topplate 32, which are held apart in substantially parallel relation by ahandle member 33 and a guide rod 34. In various embodiments, the baseplate 31 includes one or more spikes 37 for use in assisting withholding an object being compressed during operation of the deviceassociated with embodiments of the present invention. As shown in FIG.10, openings 131 are provided in the base plate 31 to receive spikes.While the handle member 33 is shown in FIG. 1 as a pair of substantiallycylindrical bodies secured to the bottom 31 and top 32 plates, it willbe appreciated that the handle member 33 can take various forms withoutcompromising the function of the present invention. For example, asshown in FIG. 2, the handle 33 can be a single member.

In the embodiment shown in FIG. 1, the guide rod 34 is a substantiallycylindrical body secured to the bottom 31 and top 32 plates. In theembodiment shown in FIG. 2, the guide rod 34 is somewhat “peanut-shaped”in cross-section and is secured to the bottom 31 and top 32 plates. Theguide rod 34 is positioned proximate to the knob assembly 40 and clampindicating assembly 50, whereas the handle member 33 is positioned awayfrom the knob assembly and clamp indicating assembly 50. The relativepositioning of the handle member 33 and the guide rod 34 assists inensuring that the plates 31 and 32 are maintained in stable position tofacilitate operation of the device embodiments. In various embodiments,the frame assembly 30, including the plates 31, 32, the handle member 33and the guide rod 34 can be formed of stainless steel, aluminum,plastic, brass and other materials of sufficient hardness and strengthfor the contemplated purposes and operations. Further, the handle member33 and the guide rod 34 can be secured to the plates 31, 32 by beingbolted, welded, soldered, pressed, captured and other known forms ofconnection. In embodiments (see FIGS. 9 and 10, for example), openings39 in the plates 31, 32 facilitate the connection with the handlemember(s) and openings 38 facilitate connection with the guide rod 34.

As shown in FIGS. 1 through 3, the knob assembly 40 employable withembodiments of the present invention can include a knob 42 and anadjustment rod 44. The knob 42 can be attached to the adjustment rod 44by being pressed, bolted, welded, soldered, pinned, threaded or beingintegrally formed, for example. The adjustment rod 44 can include a baseportion 45, an extension portion 46, and an extension segment 47 havinga groove 48 formed in the outer surface 49 thereof. In embodiments, thebase portion 45 is substantially cylindrical with a substantially smoothexterior and the extension portion 46 is also substantially cylindricaland includes a threaded exterior for engaging an actuator assembly 60 asdescribed in more detail hereafter. The extension segment 47 extendsaxially outwardly of the extension portion 46 and is adapted to extendthrough top plate 32, the actuator sleeve 62 and into a slide platform55 of the clamp indicating assembly 50, as described in more detailhereafter. A locking pin (not shown) can secure the knob assembly 40 tothe slide platform 55 by firmly engaging the groove 48 after theextension segment 47 has passed through an opening 53 in slide platform55 (see FIGS. 5 and 6). In this way, the knob assembly can influence themovement of the slide platform 55 and thus the clamp indicating assembly50, as described in more detail hereafter.

As shown in FIGS. 1, 2 and 11, the actuator assembly 60 includes anactuator sleeve 62 and an actuator button 64 extending outwardly of theouter surface 63 of the actuator sleeve 62. The actuator sleeve 62 isformed with a substantially cylindrical opening 65 having a diameter Dextending axially therethrough, wherein the opening 65 is adapted toreceive the extension portion 46 of the adjustment rod 44 of the knobassembly 40. In various embodiments, the actuator button 64 is formed incommunication with a substantially U-shaped backside ridge (not shown)on the inside of the sleeve 62, such that when the button 64 is at rest,the backside ridge extends radially inwardly of the opening 65,effectively reducing the diameter D of the opening 65. When the button64 is depressed towards the outer surface 63 of the sleeve 62, thebackside ridge on the inside of the sleeve 62 is move radiallyoutwardly, thereby restoring the full diameter D to opening 65 andpermitting free axial passage of the extension portion 46 insertedtherethrough. When the button is released, the backside ridge engagesthe extension portion 46 and holds it in axial position until such timeas the button is pressed again, or the knob is rotated. When the button64 is in the relaxed position, the extension portion 46 of knob assembly60 can still move axially through the opening 65; however, any suchmovement occurs through rotation of the extension portion 46 using knob42, for example. In this way, the outer thread of the extension portion46 threadedly engages the backside ridge of the actuator assembly 60 tothereby move through the actuator sleeve in a more controlled and slowermanner than through straight axial movement when the button 64 isdepressed. Thus, the height of the clamp indicating assembly 50 abovethe bottom plate 31 of the frame 30 can be quickly adjusted upwardly anddownwardly by depressing the actuator button 64, yet can also beadjusted more slowly and in a finer and more calculated fashion when thebutton is in the relaxed position and not pressed. It will beappreciated that the actuator assembly 60 can be provided as any of anumber of commercially available push-button actuators, and can besecured to an end of the top plate 31 by being bolted, welded, soldered,pressed, captured and through other known forms of connection. It willalso be appreciated that the thickness and pitch of the thread can bealtered through other designs to suit ergonomic demands. Other devicesbeyond that shown can be used to accomplish the same or similarfunctions as assembly 60. In embodiments of the present invention,openings 67 in the sleeve 62 and openings 69 in plate 31 (see FIGS. 9and 11) facilitate this connection.

As shown in FIGS. 1, 2 and 4 through 6, the clamp indicating assembly 50is secured to the knob assembly 40 and the guide rod 34. In variousembodiments, the guide rod 34 includes a flange member (not shown)extending radially outwardly along substantially the entire axiallyouter surface 35 of the rod 34. This flange member is adapted to engagethe inner key opening 15 of the guide sleeve 36. In alternativeembodiments, the guide rod 34 itself is keyed in the sense that it has agroove or depression 17 formed therein (see FIG. 8), wherein the groove17 extends substantially axially along the outer surface 35 of the guiderod 34. This groove is adapted to receive an extension or flange member(not shown) of the guide rod sleeve 36. In either arrangement, thesleeve 36 can smoothly and movingly engage the guide rod 34 in linearfashion during operation of the present invention as will be describedmore completely hereafter. As shown in FIGS. 1, 4 and 6, the guide rodsleeve 36 is substantially cylindrical in shape, with an opening 11extending axially therethrough, which permits the guide rod sleeve 36 toabut the outer surface 35 of the guide rod 34 for moving engagementtherewith. It will be appreciated that other shapes of items 34 and 36can be used to provide a guided single axis linear movement (see, forexample, FIG. 2).

As shown in FIGS. 1, 2 and 5 through 7, the clamp indicating assembly 50of the present invention can comprise a stem 52, a locking C-clip 54, aslide platform 55 and a load spring 56. These components assist inproviding a mounting surface for mounting and articulating end effectorssuch as rubber or other material contactors that are used to press, holdor grip elements to be worked on during operation of the presentinvention, such as a patella or appliances used to replace portions ofthe patella, for example. Stem 52 can be used to assist in holding anelement in position as additional devices aid in the patellarestoration. Stem 52 also provides a bearing surface for linear movementduring the function of applying pressure and provides a means ofmeasurement. It can be used to rotate and orientate attachments. It canrotate to allow for easy use in various positions and accommodate leftor right handed operators. The stem has a substantially hollow baseportion 51 with a “major” or larger inner diameter defined by an outerwall 150 and a “minor” or smaller inner diameter defined by a lip 152 onthe axially outer end 155 of the stem. The lip 152 helps to retain abushing (not shown) inserted into the hollow opening 157 in the baseportion 51. As further shown in FIG. 7, the stem includes a body portionouter surface 159 having substantially circumferential grooves 160, 162formed therein. A first groove 160 is formed at an axially outer endportion 164 of the stem 52 and is cooperatively engageable with aclasping member, such as locking C-clip 54 shown in FIGS. 1 and 2. Othergrooves 162 are measurement indicators that assist a user of the devicein its various embodiments in understanding the amount of pressure beingapplied to a subject element, as will be described in more detailhereafter.

As further shown in FIGS. 1, 2, 5 and 6, the clamp indicating assembly50 includes a slide platform 55 and load spring 56. The spring 56 can bepositioned around stem 52, and the stem can then be inserted throughopening 53 in the slide platform, after which the clip 54 can be lockedinto the groove 160 of stem 52. When locked, the stem 52 is thenslidably maintained within the slide platform 55, and the clip 54prevents the stem 52 from sliding all the way through the platform 55.However, the stem can be moved upward as shown in FIG. 1, where spaceexists between the clip 54 and the platform 55, and back down to aposition where the clip 54 is in contact with and directly atop theplatform 55, as shown in FIG. 2. In various embodiments, as shown inFIG. 5, for example, the slide platform 55 includes a spring guideextension 58 which extends from the inside surface 166 of the platform55 and acts to retain the spring 56 in fixed radial position, such thatthe spring can only compress and extend, without moving from side toside. The platform 55 is also provided with a concave end surface 168which is adapted to mate with the guide sleeve 36 in substantially flushrelation. The platform 55 can be secured to the guide sleeve 36 in avariety of ways, including by being bolted, welded, soldered, pressed,captured and using other known forms of connection.

Embodiments of the device can be assembled after all manufacture relatedoperations are complete by sliding spring 56 onto stem 52. These are nowslid through opening 53 in platform 55 and clip 54 is snapped into thegroove 160 on stem 52 creating assembly 50. Assembly 50 can now be slidonto guide rod 34 with the key and the slot aligned, as described above.This sub-assembly can now be set aside. Actuator assembly 60 can then beattached to top plate 32 using flat head screws or other connection, andthis sub-portion can then be set aside. Handle member(s) 33 can then bepositioned into alignment holes 39 on plate 31 and attached using buttonhead screws or in another fashion. The previously assembled clampindicating assembly 50 can then be secured to plates 31 and 32 with rodsecured within openings 38 of plate 31 and 32. The assembly 50 can bevisually aligned above the spikes 37. Now, actuator assembly 60 and knobassembly 40 are installed, and actuator assembly 60 is slid down untilthe tip of an adjusting screw is slightly above part 55. In variousembodiments, an installer can visually make sure the tip of extensionportion 46 of rod 44 aligns with the opening 53 in slide platform 55. Athrust washer 146 can then be installed onto the end of extensionportion 46 (above the slide platform 55) and a locking clip installedunderneath and into groove 48. The guide rod sleeve 36 should smoothlyslide up and down on guide rod 34 when actuated by turning knob 42. Whenall alignment is established, any untightened connectors can betightened as appropriate.

In exemplary embodiments, one can assume that a body part, such as thepatella of a human knee, is being replaced or repaired. With the variousembodiments described herein, measured pressure can be applied andaccurate positioning accommodated in restoration of the patella, forexample. In various aspects, other attachments to plate 31 or assemblies50 and/or 60 can aid this and other surgeries where accurate pressureand positioning are needed. Other embodiments and components can beincorporated into or become new devices improving or replacing existingdevices that now are outdated for their original purpose.

In a specific embodiment of operation, a medical professional such as asurgeon grasps the knob 42 of the knob assembly 40, then depresses thequick release button 64 on the actuator assembly 60. Upon depressing thequick release button 64, the adjustment rod 44 which passes through theactuator 62 and the top plate 32, and whose distal tip passes throughthe horizontal slide 55 is locked in place therein, is freed, allowingthe slide 55 to translate vertically and parallel to the guide rod 34.This motion continues until the patella mating bushing attached to thebase part 51 of the stem 52 makes direct contact with the artificialpatella prosthesis. Upon full contact, the quick release button 64 isreleased, causing the thread engagement of the adjustment rod extensionportion 46, whereupon the surgeon grasping the knob 42 can turn the knobin a clockwise motion, creating a controlled downward movementgenerating pressure upon the patella construct.

In fluid sequence, the stem portion 52 is then set and fixed upon thepatella construct, passing through the load spring 56 which butts up onthe horizontal slide 55 and the stem continues up through the horizontalslide 55 and is secured by a locking clip 54 at the most proximal partof the stem 52.

The artificial patella construct generally comprises an artificialpatella prosthesis, followed by a bonding agent, followed by a naturalpatella that has been re-surfaced for facilitating best results in theknee replacement operation. The artificial patella prosthesis ispositioned at the bottom of the clamp (in between the base plate 31 andthe stem head 51. Then, the bonding agent, such as bone cement, isapplied, and the natural resurfaced patella is then placed atop thebonding agent. Appropriate pressure must then be applied to properlysecure the artificial patella prosthesis with the natural patella.

The first segment of the clamp indicating assembly to make contact withthis patella construct is the bushing (not shown) which can be, forexample, of a rubber material in a circular design to receive a buttonstyle artificial patella prosthesis. Other contact bushings of materialsof plastic, metal and other designed to accept the geometricconfiguration of any artificial patella prosthesis replacement can beinstalled into the base 51 to facilitate operation of the presentinvention. The major inner diameter of the base 51 (described above)which receives the appropriate bushing and the minor diameter (describedabove) form an inner rim to serve as a locking mechanism to hold thespecifically designed bushing securely in place. The stem grooves 162,which have been mathematically placed to serve as reference points formeasuring pressure.

As the clamp indicating assembly 50 makes contact with the patellaconstruct, the spikes 37 can engage the patella to hold it in place. Asthe surgeon continues to turn the knob 42 in clockwise motion, morepressure is evenly applied upon the construct, as the downward motion ofthe operative parts bear down, and the load spring 56 is compressed. Asthe load spring is compressed along with the respective assembliesmoving downward, the stem proximal portion begins upward movementthrough the bore 53 of slide platform 55 as described above. Thereference markings provided by grooves 162 indicate the exactmeasurement of pressure being applied. When the prescribed rate ofpressure is achieved by the actions of the surgeon, the device can beheld in position at the desired pressure for the desired length of time.

It will be appreciated that the present invention establishes the properamount of measured applied pressure upon the patella construct on allinvolved and necessary surfaces. So after the initial establishment ofpressure, all surfaces settle in the bone cement. To the extent theelements being compressed cause the pressure to change after initiallybeing set, the pressure can be re-established. This is immediatelyrevealed by visual assessment of the indicator grooves 162 of thedevice, which has not been available heretofore. Now a failure mode canbe scientifically detected and mechanically corrected. The surgeonsimply upon viewing the deficiency through the indicator grasps handle33 in one hand and grasps knob 42 in the other, turning the knob in aclockwise motion with micro adjustment, thereby establishing orre-establishing the exact recommended pressure. The surgeon waits forfull cure of the bones cement, and can verify this thereafter. To removethe device, the surgeon takes hold of handle 33 in one hand and graspsknob 42 with the other hand and turns the knob in counter clockwisemotion to relieve the initial pressure of the device. Then with the handthat is on the handle 33, the surgeon can depress the quick releasebutton 64 and pull straight up on knob 42, then release button 64 as theassembly locks in place. The device can then be removed.

It will be appreciated that aspects of the present invention can beprovided such that the apparatus is “pre-set” to a desired or industryknown or required pressure using a single action, such as by usingactuator button 64.

FIGS. 12 through 21 show elements according to different embodiments ofan adjustable measured applied pressure clamp device employable withembodiments the present invention. As shown in the embodiment in FIG.12, the device 220 comprises a frame assembly 230 for receiving andmaintaining a clamp assembly 270, which can include a knob assembly 300and a pressure monitor assembly 330.

The frame assembly 230 can include an upper frame arm 231 and a lowerframe arm 234. In various embodiments, the upper frame arm 231 and lowerframe arm 234 comprise independent monolithic units. In otherembodiments, the upper frame arm 231 and lower frame arm 234 cancomprise multiple elements. The upper frame arm 231 can be referred toherein as an upper frame arm assembly and the lower frame arm 234 can bereferred to herein as a lower frame arm assembly, regardless of whethereach comprises a single monolithic unit or a multi-element arrangement.As shown, for example, in FIGS. 12 and 13, the lower frame arm assembly234 comprises a fixed end element 235, a bottom handle element 236 andone or more spacer elements 237. As shown in FIG. 17, for example, thefixed end element 235 is provided with an extension portion 240, a clampsupport portion 242, a top surface 244 and a bottom surface 246, withthe top surface 244 of the clamp support portion 242 adapted to receiveone or more spike elements 245 for receiving and securing elements of apatella construct or other item to be clamped or otherwise manipulatedin the receiving area 275, in accordance with the present invention. Forinstance, the top surface 244 of the clamp support portion 242 can beprovided with openings 248 that either extend through the fixed endelement 235, or that are provided as blind holes that do not extendthrough the fixed end element 235, but which can securely receive thespike elements 245. The fixed end element 235 is also provided with aslot 250 extending through the top 244 and bottom 246 surfaces of theextension portion 235, and further a side opening 252 extending from afirst side wall 254 to a second side wall (not shown) of the fixed endelement 235, and passing through the slot 250. The slot 250 is adaptedto receive a pivot nut 280 as shown in FIGS. 12 and 13, for example, andthe pivot nut 280 is movably secured to the extension portion 240 of thefixed end element 235. With reference to FIGS. 12 through 17, in variousembodiments, a pin 297 extends through the side walls (e.g., first sidewall 254) and through an opening 296 in the pivot nut collar 294 whenthe pivot nut 280 is in position within the slot 250, in order to permitthe pivot nut 280 to pivot during operation of the present invention.

As shown in FIG. 13, for example, the spacer element 237 can be providedwith a substantially cylindrical body portion having an opening (notshown) therethrough for receiving a substantially cylindrical pegelement 258. Alternatively, the peg element 258 and the spacer element237 can be integrally formed as a monolithic unit. The peg element 258is appropriately sized so as to be insertable within an opening 241 inthe extension portion 240 of the fixed end element 235, and within anopening in the bottom handle element 236. In this way, the spacerelement 237 helps secure the bottom handle element 236 to the fixed endelement 235, and helps align the receiving area 275 of the device withthe axis of the handle element 236. In this way, for example, theprinciples of operation of the device embodiments are enhanced. It willbe appreciated that various embodiments can operate with multiple spacerelements such as element 237 in order to increase the area of thereceiving area 275 for various sizes of articles and elements to beengaged in accordance with aspects of the present invention. In variousembodiments where multiple spacer elements are employed, the spacerelements can be provided such that the peg element (e.g., 258) extendsfrom an interior point within the opening of the cylindrical bodyportion to an external point outside of one side of the spacer element(e.g., 237). In this way, arrangements with multiple spacer elements canengage in a nested relationship, as a peg from a first spacer element isinserted into an opening of a second spacer element, and the peg fromthe second spacer element is inserted into the bottom handle element236, the fixed end element 235, or another spacer element according tothe employed arrangement.

As shown in FIGS. 12 and 13, the rear portion 269 of the lower frame armassembly 234 is hingedly connected to the upper frame arm 231. The upperframe arm 231 can comprise a single monolithic arm, and canalternatively comprise a curved handle section 232 and a straight handlesection 233, among other embodiments. The upper frame arm 231 can behingedly secured to the lower frame arm assembly 234 in various ways. Asshown in FIG. 13, for example, the curved handle section 232 of theupper frame arm 231 has a base portion 238 having an openingtherethrough, which can receive a pin 239 that extends through edges271, 272 of the rear portion 269 of the bottom handle element 236. Asshown in FIGS. 12 and 13, the straight handle section 233 of the upperframe arm 231 and the bottom handle element 236 can further be providedwith indentations or other forms of gripping elements 274 to facilitateoperation. The straight handle section 233 includes side wall surfaces433, a top surface 434 and a bottom surface 435, and in variousembodiments, the indentations 274 are on one or more of the side wallsurfaces 433.

As shown in the embodiments of FIGS. 12, 13, 15 and 16, the clampassembly 270 includes a pivot nut 280, a knob assembly 300 and a springmember 310, with the pivot nut 280 pivotally secured to the fixed endelement 235 at the front portion 267 of the lower frame arm assembly234, as described above. In various embodiments, the spring member 310and the pivot nut 280 can be considered part of the knob assembly 300 ofthe device of the present invention. As shown in FIGS. 15 and 16, thepivot nut 280 includes a substantially cylindrical body portion 282having an exterior wall 284 and an interior wall 286, with the interiorwall 286 forming an opening 289 in the body portion 282. In variousembodiments, the axially outer portion 291 of the interior wall 286 isthreaded so as to be capable of threadedly receiving an adjustment screwportion 302 of the knob assembly 300. In other embodiments, the fullinterior wall 286 is threaded. For example, the interior wall 286 canhave a single female receiving thread extending the length of the wall,adapted to receive a male thread on the outer surface of the adjustmentscrew 302 (see FIG. 12). The threaded engagement of the adjustment screwportion 302 of the knob assembly 300 with the interior 286 of the pivotnut body portion 282 permits the embodiments of the device to operate soas to provide increasing or decreasing clamping pressure to the articlein the receiving area 275, for example. As further shown in FIGS. 15 and16, the pivot nut 280 includes a head portion 288 having a head surface290 and a bottom surface 292, with a pivot collar 294 extending from thebottom surface 292. The pivot collar 294 can be substantially U-shapedin cross-section, with a gap 296 provided between the inner surface 295of the pivot collar 294 and the bottom surface 292 of the pivot nut head294. The gap 296 can receive the pin member 297 described above in orderto permit the pivot nut 280 to pivot about the fixed end element 235.The pivot nut 280 is further provided with a receiving end 299, whichcan abut the bottom surface 435 of the upper arm 233 to provide aresistive surface to the knob assembly 300 when the knob 304 is beingturned so as to tighten the clamping force on the object in thereceiving area 275.

As shown in FIGS. 12 and 13, the adjustment screw 302 of the knobassembly 300 extends through an opening (not shown) in the upper framearm 233 and engages the pivot nut 280. The knob assembly 300 furtherincludes a knob 304 and a washer element 306. The knob 304 is securableto the adjustment screw 302, such that rotation of the knob 304 in onedirection (e.g., clockwise) results in a tighter engagement of the screw302 with the pivot nut 280, and rotation of the knob 304 in the oppositedirection (e.g., counterclockwise) results in a loosening of theengagement between the screw 302 and pivot nut 280. Loosening therebypermits the upper arm 233 to raise higher, thereby permitting more spacein the receiving area 275. As further shown in FIGS. 12 and 13, thespring member 310 can be positioned about the exterior wall 284 of thepivot nut body 282, engaging the head surface 290 of the pivot nut headportion 288, and also engaging the bottom surface 435 of the upper arm233.

As shown in the embodiments of FIGS. 12, 13 and 14, the upper frame arm233 has a tip portion 440 formed at the end opposite the rear portion442. The tip portion 440 can be formed in various shapes, and in variousembodiments, can have a top face 444 having a width W that is wider thanthe width X of the top surface 434 of the upper frame arm 231. In thisway, the tip portion 440 is suited to support the pressure monitorassembly 330. The tip portion 440 can be provided with an interior wall(not shown) forming an opening (not shown) in the tip portion 440 forreceiving a trunk portion 335 of a clamp stem bushing 332 of thepressure monitor assembly 330. The upper frame arm tip 440 includes atop surface 444 and a bottom surface 446, and the pressure monitorassembly 330 includes a force indicator element 336 secured to andextending from the top surface 444 of the upper frame arm tip 440. Asfurther shown in FIGS. 12 through 14, 18 and 19, the pressure monitorassembly further includes a clamp stem 340 having a base portion 341 anda stem portion 342, wherein the stem portion 342 is extendable through acentral opening in the clamp stem bushing 332 and the upper frame armtip portion 440, so as to be retained in movable relation therein. Itwill be appreciated that the clamp stem bushing 332 can be formed with abase portion 333 and a trunk portion 335, with the trunk portion 335having an interior wall forming a substantially cylindrical channeltherethrough for receiving the stem portion 342 of the clamp stem 340.The base portion 333 of the clamp stem bushing 332 can be appropriatelysized to act as an alignment element for spring 370 when assembled andin operation. The stem portion 342 of the clamp stem 340 includes anouter wall 346, with a ridge 348 formed in the outer wall 346. Thepressure monitor assembly 330 further includes a ring clip member 350positioned within the ridge 348, wherein the ring clip member 350includes a lower surface 352 engageable with the top surface 444 of theupper frame arm tip 440 and/or the trunk portion 335 of the clamp stembushing 332. In this way, when the ring clip member 350 is engaged withthe top surface 444 of the upper frame arm tip 440 and/or the trunkportion 335 of the clamp stem bushing 332, the device will have apressure reading of zero. However, and as clamping action occurs on anelement within the receiving area 275, the ring clip member 250 willrise from the top surface 444 and/or trunk portion 335, and the top edge355 of the clamp stem portion 342 will rise to a measurable positionproximate the force indicator element 336 secured to and extending fromthe top surface 444 of the upper frame arm tip 440.

As shown in the embodiments of FIGS. 12 through 14, the force indicatorelement 336 can be substantially U-shaped with a first arm 337 and asecond arm 338 secured to the upper surface 444 of the upper frame armtip 440, and further wherein the force indicator element 336 includes atleast one insignia form 339 on at least one of the first 337 and second338 arms. In various embodiments, each of the first 337 and second 338arms includes a front face 360, a back face 362, an interior face 364and an exterior face 366. Further, the insignia form 339 can be providedon one or more of the front face 360, back face 362, interior face 364and exterior face 366 of one or both of the first 337 and second 338arms. The insignia form 339 provides a mechanism for determining theamount of pressure being applied to an article in the receiving area ofthe device. For instance, the location of the clamp stem portion topedge 355 in relation to the insignia form(s) 339 can be viewed from allaround the device, thereby permitting one or more individuals involvedin the operation of the present invention to visually determine andmeasure the amount of pressure being applied to an article in thereceiving area of the device. It will be appreciated that the insigniaform can be one of many forms of marking, including a physical markingdistinguished from the color or shade of the force indicator element336, as well as a defacement and or indentation on the force indicatorelement 336.

As further shown in FIGS. 12 through 14, 18 and 19, the pressure monitorassembly can further comprise a pressure monitor spring member 370positioned around the clamp stem 340 and between the top surface 372 ofthe clamp stem base portion 341 and the bottom surface 446 of the upperframe arm tip 440. The spring 370 assists in measuring the appliedpressure to the article in the receiving area 275.

As further shown in FIGS. 14 and 19 through 21, the clamp stem baseportion 341 of the clamp stem 340 can be provided with a top surface372, top surface side wall 374, intermediate surface 376, intermediateside wall 378 and a bottom surface 380, wherein the bottom surface 380has an opening 382 formed therein so as to form a compartment 384. Invarious embodiments, the bottom surface 380 has an internal radius Z,and the compartment 384 has an internal radius Y, wherein thecompartment internal radius Y is larger than the bottom surface internalradius Z so as to permit the clamp stem 340 to retain various inserts,such as insert 390 in FIGS. 20 and 21.

As shown in FIG. 21, for example, the bushing insert can comprise acontact surface adapter 390 for the clamp device, and includes a bodyportion 170, a neck portion 171 and a head portion 172, wherein the bodyportion 170, neck portion 171 and head portion 172 each have an interiorsurface (387, 388 and 389, respectively) forming an opening 395extending along an internal axis X of the bushing insert 390. In variousembodiments, the body, neck and head portions are integrally formed as amonolithic unit. As shown in FIG. 21, the body portion 170 has anaxially outer surface 396 and a radially outer surface 398, the neckportion 171 has a radially outer surface 386, and the head portion 172has an axially outer surface 391 and a radially outer surface 385. Thehead portion and neck portion interior surfaces 389 and 388, along witha portion of the body portion interior surface 387, form a substantiallycylindrical inner surface 394. The remainder of the body portioninterior surface 387 can be a substantially frustoconical surface 396 toassist in providing a gripping and mating contact with the elements ofthe patella construct during operation, as described elsewhere herein.

An exterior ledge 392 of the adapter 390 can be formed in the headportion 172 and can be substantially rounded as shown in FIGS. 20 and21. Further, the radially outer surface 386 of the neck portion forms acatching notch 399 such that, when the adapter insert 390 is positionedinto the compartment 384 of clamp stem 340, the catching notch 399 canengage the bottom surface lip 381 to snugly retain the insert 390 withinthe compartment 384. As shown in FIG. 21, the radial outer surface 386of the neck portion can have an axial height H that is comparablysmaller to the axial distances of the radial outer surfaces 385, 398 ofthe head and body portions, respectively, in order to facilitate snugand removable connection to the clamp stem as described herein. Thevarying shapes of the ledge 392, body portion external surface 398 andinterior surfaces 394, 396 can assist with the deformability of theinsert 390 to adapt to various uses as the insert 390 is deployed withinthe receiving area 275 of the device. In various embodiments, the bodyportion radially outer surface 398 has a height H that represents thelength of the insert that is exposed beyond the side wall 378 of theclamp stem 340.

As further shown in FIG. 21, the radially outer surface 385 of the headportion 172 has a radial distance R3 from the internal axis X, theradially outer surface 386 of the neck portion 171 has a radial distanceR2 from the internal axis X, and the radially outer surface 398 of thebody portion 170 has a radial distance R1 from the internal axis X.Further, the radial distance R1 of the body portion radially outersurface 398 is greater than the radial distance R3 of the head portionradially outer surface 385, and the radial distance R1 of the headportion radially outer surface 385 is greater than the radial distanceR2 of the neck portion radially outer portion 386. In this way, thebushing insert 390 is positionable and snugly retained within the clampstem 340 and 540 as shown in FIGS. 14 and 22.

In various embodiments, the radial distance R2 of the neck portionradially outer surface 386 and the radial distance R1 of the bodyportion radially outer surface 398 are substantially constant along theouter surfaces 386, 398 thereof, whereas the radial distance R3 of thehead portion radially outer surface 385 is not constant along the outersurface thereof. As shown in FIG. 21, the head portion radially outersurface 385 has an axially outer end 174, an axially inner end 176 andan axial midsection 175, and the radial distance R3 of the head portionradially outer surface 385 is greater at the axial midsection 175 thanat the axially outer 174 and inner 176 ends.

In various embodiments, the head portion radially outer surface 385 issubstantially semi-circular in cross-section, as illustrated by ledge392. The axially outer surface 396 of the body portion 170 has anaxially inner edge 373 and an axially outer edge 377, and the axiallyouter surface 396 extends axially outwardly from the axially inner edge373 to the axially outer edge 377. As further shown in FIG. 21, theaxially outer surface 396 further extends radially outwardly from theaxially inner edge 373 to the axially outer edge 377, and the bodyportion interior surface 387 extends from the neck portion interiorsurface 388 to the axially inner edge 373 of the axially outer surface396 of the body portion 170.

Assembly of the embodiments of various components shown in FIGS. 12through 21 can occur in several ways. Illustratively, the upper arm 231and lower arm assembly 234 can be assembled and connected in hingedfashion as described above, wherein the upper arm can comprise a unitarybody member, or alternatively can comprise a curved handle section 232attached to a straight handle section 233. The lower arm assembly 234can comprise a unitary body member, or alternatively an arrangementincluding a fixed end element 235, a bottom handle element 236 and oneor more spacer elements 237. The fixed end element 235 can be joinedwith the one or more spacer elements, which are then joined with thebottom handle element. The pivot nut 280 can then be pivotally connectedto the fixed end element 235 using pin 297, with the spring 310 insertedover the outer surface 284 of the pivot nut 280. Knob assembly 300 cancomprise knob 304 passing through washer 306, with the threaded screwportion 302 of the knob assembly passing through the upper arm assembly231 and into the pivot nut body portion, where the screw portion 302 canthreadingly engage the pivot nut 280. In this way, the upper frame armand lower frame arm assembly can be locked in a specific location andforce can be applied therebetween.

The pressure monitor assembly 330 can then be affixed to the clampassembly in various fashions. For instance, an insert 390 can be pushedinto the compartment 384 of the clamp stem 340. The clamp stem bushing332 can be fitted and secured through the opening in the upper arm tipportion 440, such as through welding, glue or other methods, the spring370 can be placed around the stem portion 341 of the clamp stem 340, aswell as around the base portion 333 of the clamp stem bushing 332, andthe clamp stem 340 can then be fitted through the stem bushing. Once theclamp stem 340 is through the upper arm tip portion 440, the ring member350 can be secured within the ridge 348 of the clamp stem 340, therebykeeping the clamp stem secured to the upper arm tip portion as the lowersurface 352 of the ring member 350 contacts the top surface 444 of theupper arm tip portion 440. The force indicator 336 can then be affixedto the upper arm tip portion 440. It will be appreciated that the abovedescribed illustrations of assembly can be performed in a variety ofways, and the particular order of operation described above is not thesole order for assembly.

In operation of the embodiments shown in FIGS. 12 through 21, an articleto be clamped, such as a patella construct, can be placed in thereceiving area 275 of the clamp device. In various embodiments, thearticle is first measured so as to determine an appropriately sizedinsert 390 to employ. For instance, a thin article may require a largerinsert 390, whereas a thicker article may require a smaller insert 390.In various embodiments, multiple inserts 390 of different heights H areemployed and can be interchanged within clamp stem 340. For example, afirst size insert can be provided with a height H ranging fromapproximately 25.5 mm to approximately 30 mm, a second size insert canbe provided with a height H ranging from approximately 21 mm toapproximately 25 mm, and a third size insert can be provided with aheight H ranging from approximately 15 mm to approximately 20.5 mm. itwill be appreciated that the inserts may be provided with differentheights H, with broader dimensional ranges of height H, with tighterdimensional ranges of height H, as a set of two inserts, three inserts,or any number of inserts deemed appropriate for a given application.

A portion of the article may be placed on the spike elements of thefixed end element 235 of the lower arm assembly 234. A medicalprofessional, after any necessary intermediate steps, such as securingbone cement or performing some other process on the article, can thenrotate the knob 304 so as to bring the pressure monitor assembly 330onto the article and/or to apply additional pressure on the article. Inthis way, the upper frame arm and lower frame arm assembly can be lockedin a specific location and force can be applied therebetween. The dualspring action of spring 310 about the pivot nut 280 and spring 370 aboutthe clamp stem 340 acts to resist the tension being applied by the user.Once sufficient pressure is applied to the article, any additional forceapplied through the knob assembly 300 will result in the clamp stem 340extending upwardly through the upper arm tip portion 440, whereby thetop edge 355 of the clamp stem portion 342 will rise to a measurableposition proximate the force indicator element 336 secured to andextending from the top surface 444 of the upper frame arm tip 440. Itwill be appreciated that the location of the clamp stem portion top edge355 in relation to the insignia form(s) 339 can be viewed from allaround the device, thereby permitting one or more individuals involvedin the operation of the present invention to visually determine andmeasure the amount of pressure being applied to an article in thereceiving area of the device. Once the top edge 355 is at a desiredmeasured pressure, as indicated by its location adjacent the insigniaform(s) 339, the professionals can monitor the pressure to ensure thatany pressure adaptations necessary for the required environment can beexacted through the knob assembly. For instance, if a particularprocedure requires that forty-two pounds of pressure be applied forseven minutes, and if the pressure reaches a measurement of forty-twopounds for one minute, then begins to drop, the user can rotate the knob304 to add pressure, and watch the clamp stem portion top edge 355 toensure it reaches the forty-two pound line on the indicator 336. Similarmonitoring and adjustments can occur through the seven minute duration,or whatever duration is required for a particular procedure. When theprocedure is complete, the device can be loosened through the knobassembly, and the knob can even be substantially or even entirelydisengaged from the pivot nut if necessary to allow an article to beproperly removed from the receiving area.

It will be appreciated that the present invention can provide differentforms of gauging pressure, including a light-emitting diode (LED) orother visual indicator, an auditory indicator, or other form ofindicator in lieu of or in addition to the pressure indicating element336 shown and described herein. It will also be appreciated that variousembodiments of devices described herein can employ air, water, nitrogenand other fluids in applying hydraulic pressure. Further, the deviceembodiments are adaptable to incorporate electrically and/orbattery-powered elements to apply and remove pressure. In still otherembodiments, plasma pressure, CNC technologies and/or photoelastics canbe employed. Additionally, the assembly embodiments described hereinincorporating the upper and lower arm assemblies can be adapted toimplement and measure a pulling force, to the extent a pulling force isdesired on a given article instead of a clamping force.

FIGS. 22 through 24 show an additional embodiment of the adjustablemeasured applied pressure clamp device 20 employable with embodiments ofthe present invention. As shown in the embodiment in FIG. 22, the device20 comprises a frame assembly 730 for receiving and maintaining a clampassembly 770, which can include a knob assembly 500 and a pressuremonitor assembly 530. Whereas the embodiment of the invention in FIGS.12 through 17 shows knob assembly 300 secured through the upper arm 231and pivot nut 280 movably secured to the lower arm 234, the embodimentof the invention shown in FIGS. 22 through 23 shows knob assembly 500secured through the lower arm 734 and pivot nut 780 movably secured tothe upper arm 731.

As shown in the embodiment of FIGS. 22 and 23, the frame assembly 730can include an upper frame arm 731 and a lower frame arm 734. In variousembodiments, the upper frame arm 731 and lower frame arm 734 compriseindependent monolithic units. In other embodiments of the presentinvention, the upper frame arm 731 and lower frame arm 734 can comprisemultiple elements. The upper frame arm 731 can be referred to herein asan upper frame arm assembly and the lower frame arm 734 can be referredto herein as a lower frame arm assembly, regardless of whether eachcomprises a single monolithic unit or a multi-element arrangement. Asshown, for example, in FIGS. 22 and 23, the lower frame arm assembly 734comprises a unitary arm having a handle portion 735, an angledintermediate portion 736 and an end portion 737. The end portion 737 canhave substantially the same configuration as fixed end element 235 ofFIG. 17, as described elsewhere herein. For example, the end portion 737can be provided with a top surface 444 adapted to receive one or morespike elements 745 for receiving and securing elements of a patellaconstruct or other item to be clamped or otherwise manipulated in thereceiving area 775, in accordance with the present invention. Forinstance, the top surface 744 of the clamp support portion 742 can beprovided with openings similar to openings 248 as shown in FIG. 17 anddescribed elsewhere herein.

In the embodiment shown in FIGS. 22 through 23, contrary to theembodiment shown in FIGS. 12, 13 and 17, the end portion 737 of arm 733is not provided with a slot adapted to receive a pivot nut. Rather, sucha slot 750 is provided in upper frame arm 731, as shown in FIG. 23. Aside opening 752 is also shown extending from a first side wall 754 to asecond side wall 456 of the upper arm 731, and the side opening 752 alsopasses through slot 750. Slot 750 is adapted to receive a pivot nut 780and pin 733, so as to allow the pivot nut 780 to be movably secured tothe upper arm 731, similar to how pivot nut 280 is movably secured tothe extension portion 240 of the fixed end element 235 of lower arm 231in connection with the embodiment shown in FIGS. 12 through 17.

As shown in FIGS. 22 and 23, the rear portion 769 of the lower frame armassembly 734 is hingedly connected to the upper frame arm 731, such asby a pin 703 extending through openings in the upper 734 and lower 731frame arms. The handle section 735 of the lower frame arm 731 (andoptionally portions of the upper frame arm 734) can further be providedwith indentations or other forms of gripping elements 774 to facilitateoperation. The handle section 735 includes side wall surfaces 737, a topsurface 738 and a bottom surface 739, and in various embodiments, theindentations 774 are on one or more of the side wall surfaces 737. Itwill be appreciated that the hinged connection of upper 734 and lower731 arms, along with the sloped arrangement of lower arm 731 facilitatesthe meeting of substantially parallel opposing forces in the receivingarea 775, during operation of the clamp assembly 770 of the presentinvention.

As shown in the embodiments of FIGS. 22 through 24, the clamp assembly770 includes a pivot nut 780, a knob assembly 500 and a spring member510, with the pivot nut 780 pivotally secured to the upper frame armassembly 731, as described above. In various embodiments, the springmember 510 and the pivot nut 780 can be considered part of the knobassembly 500 of embodiments of the present invention. The pivot nut 780can be substantially the same as pivot nut 280 shown in FIGS. 15 and 16and described above, including at least an axially outer portion 291 ofthe interior wall 286 that is threaded so as to be capable of threadedlyreceiving an adjustment screw portion 502 of the knob assembly 500. Thethreaded engagement of the adjustment screw portion 502 of the knobassembly 500 with the interior 286 of the pivot nut body portion 282permits the embodiments to operate so as to provide increasing ordecreasing clamping pressure to the article in the receiving area 775,for example. The adjustment screw 502 can be provided similar to theadjustment screw 302 of the knob assembly 300 shown and described inconnection with FIGS. 12 and 13, for example. A knob 504 and a washerelement 506 can also be provided similar to knob 304 and a washerelement 306 shown in FIGS. 12 and 13. Rotation of the knob 504 in onedirection (e.g., clockwise) results in a tighter engagement of the screw502 with the pivot nut 780, and rotation of the knob 504 in the oppositedirection (e.g., counterclockwise) results in a loosening of theengagement between the screw 502 and pivot nut 780. Loosening therebypermits the upper arm 731 to raise higher, thereby permitting more spacein the receiving area 775. As further shown in FIGS. 22 and 23, thespring member 510 can be positioned about the exterior wall of the pivotnut body 780, engaging the head surface 790 of the pivot nut headportion 288, and also engaging the top surface 744 of lower arm 734, oralternatively a washer 749 positioned between top surface 744 and spring510.

As shown in the embodiments of FIGS. 22 through 24, the pressure monitorassembly 530 can be provided similarly to assembly 330 of FIGS. 12through 14, including a clamp stem 540 with a base portion 541 and stemportion 542, a clamp stem bushing 532 having a trunk portion 535, andfurther including a force indicator element 536. The upper frame arm 731can be formed similar to upper frame arm 233 as described above andshown in FIGS. 12 and 13, for example, in order to fittingly receive thepressure monitor assembly 530 for operation as described herein, whereinthe clamp stem portion 542 is extendable through a central opening inthe clamp stem bushing 532 and the upper frame arm tip portion 440 ofthe upper arm 233, so as to be retained in movable relation therein. Itwill be appreciated that the clamp stem bushing 532 can be formed with abase portion 533 and a trunk portion 535, with the trunk portion 535having an interior wall forming a substantially cylindrical channeltherethrough for receiving the stem portion 542 of the clamp stem 540.The base portion 533 of the clamp stem bushing 532 can be appropriatelysized to act as an alignment element for spring 570 when assembled andin operation. The stem portion 542 of the clamp stem 340 can have aridge formed in the outer wall, and the pressure monitor assembly 530can further includes a ring clip member positioned within the ridge,wherein the ring clip member includes a lower surface engageable withthe top surface of the upper frame arm tip and/or the trunk portion 535of the clamp stem bushing 532. In this way, when the ring clip member isengaged with the top surface of the upper frame arm tip and/or the trunkportion 535 of the clamp stem bushing 532, the device will have apressure reading of zero. However, and as clamping action occurs on anelement within the receiving area 775, the ring clip member will risefrom the top surface and/or trunk portion 535, and the top edge of theclamp stem portion 542 will rise to a measurable position proximate theforce indicator element 536 secured to and extending from the topsurface of the upper frame arm tip. It will be appreciated that theclamp stem bushing can also be integrated into the upper arm assembly431/731 instead of being a separate part.

The pressure monitor spring member 570 can be positioned around theclamp stem 540 and between the top surface of the clamp stem baseportion 541 and the bottom surface of the upper frame arm tip. Thespring 570 assists in measuring the applied pressure to the article inthe receiving area 775.

The description of the clamp stem and its surfaces in connection withFIGS. 18 and 19 above are applicable to the clamp stem 540 shown anddescribed in connection with FIGS. 22 through 24. Thus, as describedabove, the clamp stem base portion 341 of the clamp stem 340 can beprovided with a top surface 372, top surface side wall 374, intermediatesurface 376, intermediate side wall 378 and a bottom surface 380,wherein the bottom surface 380 has an opening 382 formed therein so asto form a compartment 384. In various embodiments, the bottom surface380 has an internal radius Z, and the compartment 384 has an internalradius Y, wherein the compartment internal radius Y is larger than thebottom surface internal radius Z so as to permit the clamp stem 340 toretain various bushing inserts, such as insert 390 in FIGS. 20 and 21.FIGS. 22 through 24 illustrate multiple bushing inserts 390A, 390B and390C inserted into the clamp stem 540. While elements 390A, 390B and390C can be formed so as to engage one another in a nested arrangement,it will be appreciated that different bushing inserts of differentdimensions can be provided so as to adapt for smaller, medium-sized andlarger patella constructs during operation of the device. Accordingly,in various embodiments, bushing insert 390 of FIG. 21 can be used forpatella thicknesses that range from approximately 25.5 mm to 30 mm in alarger embodiment, patella thicknesses that range from approximately 21mm to 25 mm in a medium embodiment, and patella thicknesses that rangefrom approximately 15 mm to 20.5 mm in a smaller embodiment, so as toprovide clamping ability with accurate alignment as described herein.

In various embodiments, each bushing insert 390 can be made of rubberand can be provided for a single use. In this way, proper cleaning andsterilization of the metal device 20 is facilitated for each surgery,with the chances of cross-contamination between surgeries beingminimized. In various embodiments, the same three thickness bushinginserts can also be molded on the implant side to match the exact shapeof different manufactures of anatomical patella implants. When ananatomical implant is used a tab or specific feature is molded onto orin the bushing insert allowing exact radial alignment between theanatomical rubber insert and anatomical implant.

As shown in FIGS. 25 through 28, the present invention can operatewhereby, instead of an insert 390 as shown in FIG. 21, a bushing adapterdevice 880 is provided that fits around the clamp stem base portion 811instead of fitting into an opening in the clamp stem base portion. Insuch embodiments, the bushing 880 includes a head portion 893 mountedaround the side wall 810 of the clamp stem base portion 811, and theclamp stem base portion 811 does not have an opening therein.

As shown in FIGS. 25 and 26, the additional embodiment of the clamp stem840 includes a base portion 811 and a stem portion 842 having an outersurface 846, a ridge 848 and a top surface 855. The base portion 811 hasa top surface 872, a bottom side wall 810 and an intermediate ring 878having a top surface 841. An intermediate side wall 820 is positionedbetween the intermediate ring 878 and the bottom side wall 810.

As shown in FIGS. 27 and 28, the additional embodiment of the bushingadapter 880 includes a top wall 881, an outer wall 898, a clamp stemengaging surface 882, a body portion 894, a neck portion 895 and a headportion 896. In various embodiments, the body, neck and head portionsare integrally formed as a monolithic unit. The body portion 894 has aradially inner surface 884 and a radially outer surface 891, the neckportion 895 has a radially inner surface 885 and a radially outersurface 892 and the head portion 896 has a radially inner surface 886and a radially outer surface 893. The body portion 894 further has anaxially outer surface 883 that extends from an axially inner edge 890 toan axially outer edge 888 so as to form a substantially frustoconicalopening 889. The frustoconical opening assists in providing a grippingand mating contact with the elements of the patella construct duringoperation, as described elsewhere herein. The radially inner surface 886of the head portion 896 forms an interior ledge that assists in secureretention around the side wall 810 of the clamp stem as describedelsewhere herein.

As further shown in FIG. 28, the radially inner surface 886 of the headportion 896 has a radial distance R4 from the internal axis 799, theradially inner surface 885 of the neck portion 895 has a radial distanceR5 from the internal axis 799, the axially inner portion of the radiallyinner surface 884 of the body portion 894 has a radial distance R6 fromthe internal axis 799, and the axially outer portion of the radiallyinner surface 884 of the body portion has a radial distance R7 from theinternal axis. As further shown in FIG. 28, the radial distance R4 andthe radial distance R7 are variable, and the radial distances R5 and R6are substantially constant. Further, the radial distance R4 is less thanthe radial distance R5, and the radial distance R6 is less than theradial distances R4 and R5. In this way, the bushing adapter 888 is notonly positionable and snugly retained around the clamp stem 840 but alsoprovides a contact surface at the axially outer surface 883 of the bodyportion 884 that assists in providing a gripping and mating contact withthe elements of the patella construct or other elements duringoperation.

In various embodiments, the radially inner surface and/or interior ledge886 of the head portion 896 can be substantially semi-circular and/orrounded in cross-section as shown in FIGS. 27 and 28, and forms acatching notch that snugly engages the intermediate wall of the clampstem as described elsewhere herein. The varying shapes of the headportion 896, neck portion 895 and body portion 894 assist with thedeformability of the bushing adapter 888 to adapt to various uses as theadapter (with clamp stem, for example) is deployed above the receivingarea 275 of the device.

In various embodiments, the axially outer surface 883 of the bodyportion 894 extends axially outwardly from the axially inner edge 890 tothe axially outer edge 888. As further shown in FIG. 28, the axiallyouter surface 883 further extends radially outwardly from the axiallyinner edge 890 to the axially outer edge 888, and the body portioninterior surface 884 extends from the clamp stem engaging surface 882 tothe axially inner edge 890 of the axially outer surface 883 of the bodyportion 894. In various embodiments, the radial distances to each of theradially outer surfaces 892 and 893 of at least the neck portion 895 andhead portion 896 are substantially the same. In various additionalembodiments, the radial distances to each of the radially outer surfaces891, 892 and 893 of the body portion 894, neck portion 895 and headportion 896 are substantially the same, thereby providing asubstantially cylindrical outer surface to the adapter 880.

In operation, the adapter 888 of FIGS. 27 and 28 can be positionedaround the bottom side wall 810 of the clamp stem 840 of FIGS. 25 and26, such that the radially inner surface 886 of the head portion 896 ofthe adapter 888 engages the intermediate side wall 820 of the clamp stem840 and the radially inner surface 885 of the neck portion 895 of theadapter 888 engages the bottom side wall 810 of the clamp stem 840. Theclamp stem engaging surface 882 engages the bottom surface 812 of theclamp stem 840. In this way, the adapter 888 is securely retained aboutthe clamp stem base 811 and can appropriately engage elements of thepatella construct or other elements brought into the clamping area to beclamped.

It will further be appreciated that the present invention can be adaptedsuch that the spike elements 745 are positioned on the clamp stem baseportion 341/541/811 depending from the upper arm 231 and the insert(s)390 are provided on the lower arm 234.

As shown in FIGS. 31 through 33, in another embodiment of the presentinvention, an installation cap 800 is provided for assistance withproper setup and operation of the present invention. The cap 800 can beprovided with a base 802 having a side wall 804, a top wall 806 and aback wall 808, and is further provided with a substantially cylindricaltrunk 810 having an outer surface 812 and an inner surface 814 thatdefines an opening 820 extending through the cap 800. Edges of the base802 and trunk 810 portions can be chamfered to provide a finishedelement with a surface that may be more readily engaged by a finger,fingernail or other element capable of poking the cap from its initiallyinstalled position. The cap 800 can be installed in the opening 830 ofthe fixed end element 235 of the lower frame arm assembly 234/734 suchthat the trunk outer surface 812 engages the inner surface of the fixedend element 235 defining the opening 830. In this way, the base 802 ofthe cap 800 extends into the receiving area 775 between the fixed endelement 235 (FIGS. 12-13) or end element 737 of lower frame arm 734(FIGS. 22-23) and the insert 390. The base 802 also covers up the spikeelements 745, such that a user that seeks to install an insert 390 justbefore a procedure is to take place will be protected from minorabrasion.

It will further be appreciated that various embodiments of the presentinvention can employ various material types, including but notrestricted to stainless steel, aluminum, brass, plastics and highstrength composites, for example.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the claims of the application rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

The invention claimed is:
 1. A contact surface adapter for a clamp,comprising: a bushing having a body portion, a neck portion and a headportion, wherein the body portion, neck portion and head portion eachhave an interior surface forming an opening extending along an internalaxis of the bushing, wherein the body portion has an axially outersurface and a radially outer surface, the neck portion has a radiallyouter surface, and the head portion has an axially outer surface and aradially outer surface; wherein the radially outer surface of the headportion has a radial distance from the internal axis, the radially outersurface of the neck portion has a radial distance from the internalaxis, and the radially outer surface of the body portion has a radialdistance from the internal axis, and further wherein the radial distanceof the body portion radially outer surface is greater than the radialdistance of the head portion radially outer surface, wherein the radialdistance of the head portion radially outer surface is greater than theradial distance of the neck portion radially outer surface, and whereinthe head portion radially outer surface has an axially outer end, anaxially inner end and an axial midsection, and wherein the radialdistance of the head portion radially outer surface is greater at theaxial midsection than at the axially outer and inner ends.
 2. Theadapter of claim 1, wherein the radial distance of the neck portionradially outer surface is substantially constant and the radial distanceof the body portion radially outer surface is substantially constant. 3.The adapter of claim 1, wherein the head portion radially outer surfaceis substantially semi-circular in cross-section.
 4. The adapter of claim1, wherein the axially outer surface of the body portion has an axiallyinner edge and an axially outer edge, and wherein the axially outersurface extends axially outwardly from the axially inner edge to theaxially outer edge.
 5. The adapter of claim 4, wherein the axially outersurface further extends radially outwardly from the axially inner edgeto the axially outer edge.
 6. The adapter of claim 4, wherein the bodyportion interior surface extends from the neck portion interior surfaceto the axially inner edge of the axially outer surface of the bodyportion.